//
// Created by 罗玉龙 on 2017/5/26.
//

#ifndef PAYDEMO_MD5_H
#define PAYDEMO_MD5_H


#include <string>
#include <fstream>

/* Type define */
typedef unsigned char byte;
typedef unsigned int uint32;

using std::string;
using std::ifstream;

/* MD5 declaration. */
class MD5 {
public:
    MD5();
    MD5(const void *input, size_t length);
    MD5(const string &str);
    MD5(ifstream &in);
    void update(const void *input, size_t length);
    void update(const string &str);
    void update(ifstream &in);
    const byte* digest();
    string toString();
    void reset();
private:
    void update(const byte *input, size_t length);
    void final();
    void transform(const byte block[64]);
    void encode(const uint32 *input, byte *output, size_t length);
    void decode(const byte *input, uint32 *output, size_t length);
    string bytesToHexString(const byte *input, size_t length);

    /* class uncopyable */
    MD5(const MD5&);
    MD5& operator=(const MD5&);
private:
    uint32 _state[4]; /* state (ABCD) */
    uint32 _count[2]; /* number of bits, modulo 2^64 (low-order word first) */
    byte _buffer[64]; /* input buffer */
    byte _digest[16]; /* message digest */
    bool _finished; /* calculate finished ? */

    static const byte PADDING[64]; /* padding for calculate */
    static const char HEX[16];
    static const size_t BUFFER_SIZE = 1024;
};



#endif //PAYDEMO_MD5_H
